(Bloomberg) -- Activist investor Blue Harbour Group disclosed a new stake in restaurant chain Jack in the Box Inc. and may push for changes at the company. Greenwich, Connecticut-based Blue Harbour owns a 6.8 percent stake in the fast-food company and believes it is undervalued, according to a regulatory filing. The investor thinks Jack in the Box made the right decision to sell Qdoba Restaurant Corp. and divest a majority of its remaining company-owned units...